Neuroimaging of disorders of arousal and other parasomnias

The neuroimaging studies have provided new information about brain abnormalities in narcolepsy patients. Differences in brain morphology that are not identifiable by routine visual inspection of individual brain magnetic resonance imaging (MRI) can be investigated using voxel-based morphometry (VBM). The VBM method has some limitations in representing gray matter morphology, and localization in the sulcal regions where the fine details of the anatomy are often obscured by a partial volume effect. On the other hand, the thickness of the cerebral cortex reflects the density and arrangement of cells. Measuring cortical thickness using the cortical surface method has been suggested in studies of gray matter morphometry as a strategy for overcoming the limitation of volumetric analyses. Higher tesla MRI scanners and further development of analysis software of brain MR images are able to better characterize the structural changes in narcoleptic brains.